Every night before he goes to beb, 84-year old Tim Reilly goes through a strange ritual: first, he makes sure the dining room light at the front of the house is left on; then he checks that the handwritten note on the front door is secure

Tim has done the same things every night for the past nine years but every night his greatest hope is that it's the last night he'll ever have to do it. "Because what I want more than anything," he says, "is for my son Matthew to come home. The note on the door says 'Welcome home Matthew, ring the bell.' It would be the best thing I can imagine if I was woken up one night by that bell and Matthew was standing there on the doorstep"